Skip to content

Collective pinning of a frozen vortex liquid in ultrathin superconducting YBa2Cu3O7 films

M. Calame, S. E. Korshunov, Ch. Leemann, P. Martinoli

cond-mat.supr-conarXiv:cond-mat/0009308

Abstract

The linear dynamic response of the two-dimensional (2D) vortex medium in ultrathin YBa2Cu3O7 films was studied by measuring their ac sheet impedance Z over a broad range of frequencies ω. With decreasing temperature the dissipative component of Z exhibits, at a temperature T*(ω) well above the melting temperature of a 2D vortex crystal, a crossover from a thermally activated regime involving single vortices to a regime where the response has features consistent with a description in terms of a collectively pinned vortex manifold. This suggests the idea of a vortex liquid which, below T*(ω), appears to be frozen at the time scales 1/ωof the experiments.

Create a lesson